
[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR7]

[Page 76-80]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 7--TESTING BY APPLICANT OR THIRD PARTY--Table of Contents
 
Subpart K--Electric Cables, Signaling Cables, and Cable Splice Kits

    Source: 57 FR 61220, Dec. 23, 1992, unless otherwise noted.

Sec. 7.401  Purpose and effective date.

    This subpart establishes the flame-resistant requirements for 
approval of electric cables, signaling cables and cable splice kit 
designs. Applications for approval or extension of approval submitted 
after February 22, 1994 shall meet the requirements of this subpart.

Sec. 7.402  Definitions.

    The following definitions apply in this subpart.
    Component. Any material in a cable splice kit which becomes part of 
a splice.
    Conductor. A bare or insulated wire or combination of wires not 
insulated from one another, suitable for carrying an electric current.
    Electric Cable. An assembly of one or more insulated conductors of 
electric current under a common or integral jacket. A cable may also 
contain one or more uninsulated conductors.
    Jacket. A nonmetallic abrasion-resistant outer covering of a cable 
or splice.
    Power Conductor. An insulated conductor of a cable assembly through 
which the primary electric current or power is transmitted.
    Signaling Cable. A fiber optic cable, or a cable containing electric 
conductors of a cross-sectional area less than 14 AWG used where the 
circuit cannot deliver currents which would increase conductor 
temperatures beyond that established for the current-carrying capacity 
of the conductors.

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    Splice. The mechanical joining of one or more severed conductors in 
a single length of a cable including the replacement of insulation and 
jacket.
    Splice Kit. A group of materials and related instructions which 
clearly identify all components and detail procedures used in safely 
making a flame-resistant splice in an electric cable.

Sec. 7.403  Application requirements.

    (a) Electric cables and signaling cables. A single application may 
address two or more sizes, types, and constructions if the products do 
not differ in composition of materials or basic design. Applications 
shall include the following information for each product:
    (1) Product information:
    (i) Cable type (for example, G or G-GC).
    (ii) Construction (for example, round or flat).
    (iii) Number and size (gauge) of each conductor.
    (iv) Voltage rating for all cables containing electric conductors.
    (v) For electric cables, current-carrying capacity of each 
conductor, with corresponding ambient temperature upon which the current 
rating (ampacity) is based, of each power conductor.
    (2) Design standard. Specify any published consensus standard used 
and fully describe any deviations from it, or fully describe any 
nonstandard design used.
    (3) Materials. Type and identifying numbers for each material 
comprising the finished assembly.
    (b) Splice kit. A single application may address two or more sizes, 
types, and constructions if the products do not differ in composition of 
materials or basic design. Applications shall include the following 
information for each product:
    (1) Product information:
    (i) Trade name or designation (for example, style or code number).
    (ii) Type or kit (for example, shielded or nonshielded).
    (iii) Voltage rating.
    (2) Design standard. Specify any published design standard used and 
fully describe any deviations from it, or provide complete final 
assembly dimensions for all components for each cable that the splice 
kit is designed to repair.
    (3) Materials. Type of materials, supplier, supplier's stock number 
or designation for each component.
    (4) Complete splice assembly instructions which clearly identify all 
components and detail procedures used in making the splice.

Sec. 7.404  Technical requirements.

    (a) Electric cables and splices shall be flame resistant when tested 
in accordance with Sec. 7.407.
    (b) Signaling cables shall be flame resistant when tested in 
accordance with Sec. 7.408.

Sec. 7.405  Critical characteristics.

    (a) A sample from each production run, batch, or lot of manufactured 
electric cable, signaling cable, or splice made from a splice kit shall 
be flame tested, or
    (b) A sample of the materials that contribute to the flame-resistant 
characteristic of the cable or splice and a sample of the cable or 
splice kit assembly shall be visually inspected or tested through other 
means for each production run, batch, or lot to ensure that the finished 
product meets the flame-resistance test.

Sec. 7.406  Flame test apparatus.

    The principal parts of the apparatus used to test for flame 
resistance of electric cables, signaling cables and splices shall 
include:
    (a) Test chamber. A rectangular enclosure measuring 17 inches deep 
by 14\1/2\ inches high by 39 inches wide and completely open at the top 
and front. The floor or base of the chamber shall be fabricated or lined 
with a noncombustible material that will not extinguish burning matter 
which may fall from the test specimen during testing. The chamber shall 
have permanent connections mounted to the back wall, sides, or floor of 
the chamber which extend to the sample end location. These are used to 
energize the electric cable and splice specimens. They are not used, but 
may stay in place, when testing signaling cables.
    (b) Specimen holder (support). A specimen holder (support) 
consisting of

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three separate metal rods each measuring approximately \3/16\ inch in 
diameter (nominal) to support the specimen. The horizontal portion of 
the rod which contacts the test specimen shall be approximately 12 
inches in length.
    (c) Gas ignition source. A standard natural gas type Tirrill burner, 
with a nominal inside diameter of \3/8\ inch, to apply the flame to the 
test specimen. The fuel for the burner shall be natural gas composed of 
at least 96 percent combustible hydrocarbons, with at least 80 percent 
being methane.
    (d) Current source. (For electric cables and splices only). A source 
of electric current (either alternating current or direct current) for 
heating the power conductors of the test specimen. The current source 
shall have a means to regulate current flow through the test specimen 
and have an open circuit voltage not exceeding the voltage rating of the 
test specimen.
    (e) Current measuring device. (For electric cables and splices 
only). An instrument to monitor the effective value of heating current 
flow through the power conductors of the specimen within an accuracy of 
<plus-minus>1 percent.
    (f) Temperature measuring device. (For electric cables and splices 
only). An instrument to measure conductor temperature within an accuracy 
of <plus-minus>2 percent without the necessity of removing material from 
the test specimen in order to measure the temperature.

Sec. 7.407  Test for flame resistance of electric cables and cable 
          splices.

    (a) Test procedure. (1) For electric cables, prepare 3 specimens of 
cable, each 3 feet in length, by removing 5 inches of jacket material 
and 2\1/2\ inches of conductor insulation from both ends of each test 
specimen. For splices, prepare a splice specimen in each of 3 sections 
of MSHA-approved flame-resistant cable. The cable shall be of the type 
that the splice kit is designed to repair. The finished splice shall not 
exceed 18 inches or be less than 6 inches in length for test purposes. 
The spliced cables shall be 3 feet in length with the midpoint of the 
splice located 14 inches from one end. Both ends of each of the spliced 
cables shall be prepared by removing 5 inches of jacket material and 
2\1/2\ inches of conductor insulation. The type, amperage, voltage 
rating, and construction of the cable shall be compatible with the 
splice kit design. Each splice shall be made in accordance with the 
instructions provided with the splice kit.
    (2) Prior to testing, condition each test specimen for a minimum of 
24 hours at a temperature of 70<plus-minus>10  deg.F 
(21.1<plus-minus>5.5  deg.C) and a relative humidity of 55<plus-minus>10 
percent. These environmental conditions shall be maintained during 
testing.
    (3) For electric cables, locate the sensing element of the 
temperature measuring device 26 inches from one end of each test 
specimen. For splices, locate the sensing element 12 inches from the 
midpoint of the splice and 10 inches from the end of the cable. The 
sensing element must be secured so that it remains in direct contact 
with the metallic portion of the power conductor for the duration of the 
flame-resistant test. If a thermocouple-type temperature measuring 
instrument is used, connect the sensing element through the cable jacket 
and power conductor insulation. Other means for monitoring conductor 
temperature may be used, provided the temperature measurement is made at 
the same location. If the jacket and conductor insulation must be 
disturbed to insert the temperature measuring device, each must be 
restored as closely as possible to its original location and maintained 
there for the duration of the testing.
    (4) Center the test specimen horizontally in the test chamber on the 
three rods. The three rods shall be positioned perpendicular to the 
longitudinal axis of the test specimen and at the same height, which 
permits the tip of the inner cone from the flame of the gas burner, when 
adjusted in accordance with the test procedure, to touch the jacket of 
the test specimen. The specimen shall be maintained at this level for 
the duration of the flame test. The two outermost rods shall be placed 
so that 1 inch of cable jacket extends beyond each rod. For electric 
cables, the third rod shall be placed 14 inches from the end of the test 
specimen nearer the temperature monitoring location on the specimen. For 
splices, the third rod shall be placed between the splice and the 
temperature monitoring

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location at a distance 8 inches from the midpoint of the splice. The 
specimen shall be free from external air currents during testing.
    (5) Adjust the gas burner to give an overall blue flame 5 inches 
high with a 3-inch inner cone. There shall be no persistence of yellow 
coloration.
    (6) Connect all power conductors of the test specimen to the current 
source. The connections shall be secure and compatible with the size of 
the cable's power conductors in order to reduce contact resistance.
    (7) Energize all power conductors of the test specimen with an 
effective heating current value of 5 times the power conductor ampacity 
rating (to the nearest whole ampere) at an ambient temperature of 104 
deg.F (40  deg.C).
    (8) Monitor the electric current through the power conductors of the 
test specimen with the current measuring device. Adjust the amount of 
heating current, as required, to maintain the proper effective heating 
current value within <plus-minus>5 percent until the power conductors 
reach a temperature of 400  deg.F (204.4  deg.C).
    (9) For electric cables, apply the tip of the inner cone from the 
flame of the gas burner directly beneath the test specimen for 60 
seconds at a location 14 inches from one end of the cable and between 
the supports separated by a 16-inch distance. For splices, apply the tip 
of the inner cone from the flame of a gas burner for 60 seconds beneath 
the midpoint of the splice jacket.
    (10) After subjecting the test specimen to external flame for the 
specified time, fully remove the flame of the gas from beneath the 
specimen without disturbing air currents within the test chamber. 
Simultaneously turn off the heating current.
    (11) Record the amount of time the test specimen continues to burn 
after the flame from the gas burner has been removed. The duration of 
burning includes the burn time of any material that falls from the test 
specimen after the flame from the gas has been removed.
    (12) Record the length of burned (charred) area of each test 
specimen measured longitudinally along the cable axis.
    (13) Repeat the procedure for the remaining two specimens.
    (b) Acceptable performance. Each of the three test specimens shall 
meet the following criteria:
    (1) The duration of burning shall not exceed 240 seconds.
    (2) The length of the burned (charred) area shall not exceed 6 
inches.

Sec. 7.408  Test for flame resistance of signaling cables.

    (a) Test procedure. (1) Prepare 3 samples of cable each 2 feet long.
    (2) Prior to testing, condition each test specimen for a minimum of 
24 hours at a temperature of 70<plus-minus>10  deg.F 
(21.1<plus-minus>5.5  deg.C) and relative humidity of 55<plus-minus>10 
percent. These environmental conditions shall be maintained during 
testing.
    (3) Center the test specimen horizontally in the test chamber on the 
three rods. The three rods shall be positioned perpendicular to the 
longitudinal axis of the test specimen and at the same height, which 
permits the tip of the inner cone from the flame of the gas burner, when 
adjusted in accordance with the test procedure, to touch the test 
specimen. The specimen shall be maintained at this height for the 
duration of the flame test. The two outermost rods shall be placed so 
that 1 inch of cable extends beyond each rod. The third rod shall be 
placed at the midpoint of the cable. The specimen shall be free from 
external air currents during testing.
    (4) Adjust the gas burner to give an overall blue flame 5 inches 
high with a 3-inch inner cone. There shall be no persistence of yellow 
coloration.
    (5) Apply the tip of the inner cone from the flame of the gas burner 
for 30 seconds directly beneath the specimen centered between either and 
support and the center support.
    (6) After subjecting the test specimen to external flame for the 
specified time, fully remove the flame of the gas from beneath the 
specimen without disturbing air currents within the test chamber.
    (7) Record the amount of time the test specimen continues to burn 
after the flame from the gas burner has been removed. The duration of 
burning includes the burn time of any material

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that falls from the test specimen after the flame from the gas has been 
removed.
    (8) Record the length of burned (charred) area of each test specimen 
measured longitudinally along the cable axis.
    (9) Repeat the procedure for the remaining two specimens.
    (b) Acceptable performance. Each of the three test specimens shall 
meet the following criteria:
    (1) The duration of burning shall not exceed 60 seconds.
    (2) The length of the burned (charred) area shall not exceed 6 
inches.

Sec. 7.409  Approval marking.

    Approved electric cables, signaling cables, and splices shall be 
legibly and permanently marked with the MSHA-assigned approval marking. 
For electric cables and signaling cables, the marking shall appear at 
intervals not exceeding 3 feet and shall include the MSHA-assigned 
approval number in addition to the number and size (gauge) of conductors 
and cable type. For cables containing electric conductors, the marking 
shall also include the voltage rating. For splices, the marking shall be 
placed on the jacket so that it will appear at least once on the 
assembled splice.

Sec. 7.410  Post-approval product audit.

    Upon request by MSHA, but no more than once a year except for cause, 
the approval holder shall supply to MSHA for audit at no cost--
    (a) 12 feet of an approved electric cable or approved signaling 
cable; or
    (b) 3 splice kits of one approved splice kit design and 12 feet of 
MSHA-assigned cable that the splice kit is designed to repair.

Sec. 7.411  New technology.

    MSHA may approve cable products or splice kits that incorporate 
technology for which the requirements of this subpart are not applicable 
if the Agency determines that they are as safe as those which meet the 
requirements of this subpart.

                           PART 11 [Reserved]
